Capacity space savings are due to deduplication+compression and include both storage and backups.

90% savings is the equivalent of 10:1 efficiency in the Datacenter panel in the HPE SimpliVity tab within the vSphere Client. Efficiency is calculated across all HPE SimpliVity systems in a VMware Datacenter. It’s the ratio of storage capacity that would have been used on a comparable traditional storage solution to the physical storage that is actually used in the HPE SimpliVity hyperconverged infrastructure. ‘Comparable traditional solutions’ are storage systems that provide VM-level synchronous replication for storage and backup and do not include any deduplication or compression capability.

The savings/efficiency are based on the assumption that you configure a backup policy to take at least one HPE SimpliVity backup per day of every virtual machine on every HPE SimpliVity system in a given VMware Datacenter with those backups retained for 30 days. If backups are performed more frequently and/or retained for a longer period, you will enjoy even greater efficiency. The data change rate is assumed to be up to 5% per day with up to 30% growth rate of the data over a duration of 30 contiguous days.